Tunnelling machines

ABSTRACT

A tunnelling machine comprises a cutting head mounted on a cylindrical shield which has a sole plate adjacent its front end and at its lowest part. In use, the machine also comprises a sledge which slides behind the shield, the sledge being connected to the shield by a steering arm. Means are provided for altering the angle between the steering arm and the longitudinal axis of the shield to steer the machine by rocking or pivoting it about the sole plate.

United States Patent [191 Bland 1 TUNNELLING MACHINES [75] Inventor: John Bland, London, England [73] Assignee: Sir Robert McAlpine & Sons Limited, London, England [22] Filed: Apr. 18, 1974 [21] Appl. No.: 461,924

[30] Foreign Application Priority Data Apr. 30, 1973 United Kingdom 20486/73 [52] US. Cl. 299/31; 61/85; 299/33 [51] Int. Cl. E21C 29/00; E21D 9/08 [58] Field of Search 61/84, 85; 299/31, 33

[56] References Cited UNITED STATES PATENTS 3,410,098 11/1968 Winberg 61/85 3,420,577 l/1969 Pentith 299/31 1 Sept. 16, 1975 3,468,133 9/1969 Matsushita 299/31 X 3,523,426 8/1970 Lauber 61/85 3,598,445 8/1971 Winberg 299/31 3,830,545 8/1974 Sugden 299/33 Primary ExaminerPaul R. Gilliam Assistant Examiner-David H. Corbin Attorney, Agent, or Firm Edward P. Connors [5 7] ABSTRACT A tunnelling machine comprises a cutting head mounted on a cylindrical shield which has a sole plate adjacent its front end and at its lowest part. In use, the machine also comprises a sledge which slides behind the shield, the sledge being connected to the shield by a steering arm. Means are provided for altering the angle between the steering arm and the longitudinal axis of the shield to steer the machine by rocking or pivoting it about the sole plate.

9 Claims, 2 Drawing Figures PATENYEU SE? 1 61975 SHEET 1 [IF 2 PAIENIEU EP 1 8 5 3,905,645

SHE T 2 BF 2 TUNNELLING MACHINES This invention enables a tunnelling shield as used in -soft ground tunnelling to be steered when in a rock environment thus creating ameans for a single comprehensive all purpose tunnelling machine to be designed capable of dealing with both soft ground and hard rock conditions.

SUMMARY vor; THE INVENTION.

The invention provides a tunnelling machine comprising aa cutting head mounted ona cylindrical shield, the shield having a sole plate adjacent the front end of the shield and at the lowest part of the shield, in use, the machine also comprising a sledge which slides behind the shield, said sledge being connected to the shield by a steering arm and in which'means are provided for altering the angle between the steering arm and the longitudinal axis of the shield to steer the machine, by rocking or pivoting it about the sole plate.

It is preferred that the steering arm is pivotally attached to the shield and there is jacking means to alter the said angle.

Preferably the steering arm is pivotally attached to ,the shield at or adjacent the longitudinal axis of the shield.

In one embodiment the steering arm also provides a support for a spoil removing conveyor.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT As will be seen from the drawings the machine comprises a cylindrical shield on which is mounted a cutting head indicated generally at 11 by means of=a central bearing assembly 12. The cutting head forms no part of the present invention and will not be described in detail except to explain that the cutting head, can be arranged to cut a tunnel having a larger diameter than the shield, when in a rock environment. When the machine is in a soft ground environment, the cutting head is arranged to cut a tunnel of a slightly smaller diameter than the shield, and the leading edge of the shield cuts out the remaining part.

The shield has a forward extension 14 and a sole plate 15 is attached to the forward edge of the part 14. The sole plate extends only around the lower part of the circumference of the shield and provides a rocking pad and also a rubble seal.

Immediately behind the shield there is an expanding ring assembly 16 which is expandable into contact with the wall of the tunnel. The shield is driven forwardly by means of hydraulic rams l7 spaced around the periphery of the shield and having pistons 18 which are engageablewith the expanding ring 16.

Behind the machine there is a sledge 19 which is the furthest forward of a number of sledges which are conventionally used to carry services for the machine. A steering truss 20 is pivotally attached to the-shield 10 on a mounting 21 adjacent the axis of the shield. The truss 20 is alsosupported on the forward end of the sledge 19. Two hydraulic jacks 2 3;one on either side of the centre line of the machine are arranged to be able to alter the angle between the steering truss 20 and the central axis of the shield 10. Each of the jacks 23 is pivotally mounted to.a bracket 24 attached to the shield and to alink 25 which-is in turn pivotally attached to a bracket 26 on the steering truss.

The steering truss also forms a mounting for a spoil removal conveyor 27 fed byia hopper 28 from the cutting head in conventional manner.

The sledge also forms a mounting for a conveyor 32 which is used to transport'segments 33 which make up the tunnel lining. Each segment is transferred from the conveyor 32 to a support pad 34 of the segment erector which is then moved by means of rams 30, 31 to put the segment 'in position against the wall of the tunnel.

As the shield is moved forwards thetail end of the machine is kept in its correct attitude by means of the steering truss 20 resting on the sledge 19. The sledge 19 may either run along the bottom of the tunnel or on rails.

When the shield has advanced so far that the rams 17 are fully extended the next stage is to retract the rams and to move the expanding ring 16 forwards. In this case it may be necessary to lock the truss 20 to the sledge 19 and this may be done in any convenient manner. For instance a nut (not shown) held captive on the sledge can be engaged by means of a screw passing through any one of a series of holes (not shown) on the truss. When the expanding ring 16 has been moved forward, more tunnel lining segments 33 may be put in place.

It is of course possible to use the machine in soft ground as well as in hard ground in the manner just described. In this case the cutting head cuts a tunnel of the same size or slightly smaller than the diameter of the shield and the shield can be steered forwards either by using the rams 18 in conventional manner or the rams 23.

The rams 18 can also assist steering in hard ground,

and furthermore in both soft and hard ground conditions the rams 18 and the rams 23 may be used in combination to facilitate steering of the machine.

Any type of cutter whether drag picks or disc, roller or button cutters may be mounted on the cutting head as appropriate to ground conditions and the cutters should be readily interchangeable to facilitate movement from one type of ground to another.

I claim:

1. A tunnelling machine for boring a circular tunnel in the earth comprising:

i a cylindrical shield for supporting the wall of a tunnel as it is bored with the shield having a forward and rearward end;

ii a plurality of hydraulic rams;

iii means mounting the rams on the shield for reacting against fixed means in the tunnel behind the shield to advance the shield;

iv a cutting head;

v means mounting the cutting head at the forward end of the shield for rotation about the central axis of the shield to cut the tunnel;

vi a sole plate attached to the cylindrical shield adjacent the forward end of the shield and at the lowest part of the shield;

vii a sledge;

viii means to allow the sledge to move along the tunnel behind the shield supported by the floor of the tunnel;

ix a steering arm;

x means to pivotally attach one end of the arm to the shield adjacent the longitudinal axis of the shield;

xi means to support the other end of the steering arm on the sledge such that the whole reaction from the steering arm is always taken by the sledge;

xii a single pair of hydraulic steering jacks;

xiii means pivotally connecting one end of each of the hydraulic jacks to the steering arm, and

xiv means pivotally connecting the other end of each of the hydraulic jacks to the periphery of the shield at the lower part of the shield, one each side of the 2. A tunnelling machine as claimed in claim 1 in which the fixed means in the tunnel comprises a reaction ring, means being provided to expand the ring radially to grip the wall of the tunnel.

3. A tunnelling machine as claimed in claim 1 in which the rams are operable to provide additional steering of the machine.

4. A tunnelling machine as claimed in claim 1 in which the cutting head has cutters which are readily interchangeable to facilitate conversion as the machine moves from hard to soft ground.

5. A tunnelling machine as claimed in claim 1 for tunnelling in soft ground, in which the cutting head is operable to cut a tunnel'of a diameter not larger'than the diameter of the shield.

6. A tunnelling machine as claimed in claim 1 for tunnelling in hard ground, in which the cutting head is operable to cut a tunnel of larger diameter than the shield.

7. A tunnelling machine as claimed in claim 1 in which means are provided to lock the steering arm to the sledge.

8. A tunnelling machine as claimed in claim 1 in which the steering arm provides a support for a spoil removal conveyor.

9. A tunnelling machine as claimed in claim 1 in which the steering arm provides a support for a segment erector. 

1. A tunnelling machine for boring a circular tunnel in the earth comprising: i a cylindrical shield for supporting the wall of a tunnel as it is bored with the shield having a forward and rearward end; ii a plurality of hydraulic rams; iii means mounting the rams on the shield for reacting against fixed means in the tunnel behind the shield to advance the shield; iv a cutting head; v means mounting the cutting head at the forward end of the shield for rotation about the central axis of the shield to cut the tunnel; vi a sole plate attached to the cylindrical shield adjacent the forward end of the shield and at the lowest part of the shield; vii a sledge; viii means to allow the sledge to move along the tunnel behind the shield supported by the floor of the tunnel; ix a steering arm; x means to pivotally attach one end of the arm to the shield adjacent the longitudinal axis of the shield; xi means to support the other end of the steering arm on the sledge such that the whole reaction from the steering arm is always taken by the sledge; xii a single pair of hydraulic steering jacks; xiii means pivotally connecting one end of each of the hydraulic jacks to the steering arm, and xiv means pivotally connecting the other end of each of the hydraulic jacks to the periphery of the shield at the lower part of the shield, one each side of the shield, each jack being inclined at an acute angle to the vertical as viewed along the longitudinal axis of the shield, so that the angle between the steering arm and the longitudinal axis of the shield may be controlled by the jacks to steer the machine by pivoting it about the sole plate.
 2. A tunnelling machine as claimed in claim 1 in which the fixed means in the tunnel comprises a reaction ring, means being provided to expand the ring radially to grip the wall of the tunnel.
 3. A tunnelling machine as claimed in claim 1 in which the rams are operable to provide additional steering of the machine.
 4. A tunnelling machine as claimed in claim 1 in which the cutting head has cutters which are readily interchangeable to facilitate conversion as the machine moves from hard to soft ground.
 5. A tunnelling machine as claimed in claim 1 for tunnelling in soft ground, in which the cutting head is operable to cut a tunnel of a diameter not larger than the diameter of the shield.
 6. A tunnelling machine as claimed in claim 1 for tunnelling in hard ground, in which the cutting head is operable to cut a tunnel of larger diameter than the shield.
 7. A tunnelling machine as claimed in claim 1 in which means are provided to lock the steering arm to the sledge.
 8. A tunnelling machine as claimed in claim 1 in which the steering arm provides a support for a spoil removal conveyor.
 9. A tunnelling machine as claimed in claim 1 in which the steering arm provides a support for a segment erector. 